U.S. Pat. No. 4,207,468 (Wilson) discloses a system for identifying vehicles, each carrying an infrared transponder, as they enter or exit a parking facility. An interrogator unit at a fixed location (at the entry or exit of the parking facility) senses the approach of the vehicle and transmits a sequence of interrogating light pulses to a transponder on the approaching vehicle. The transponder uses the interrogator pulses to clock its own transmission back to the fixed interrogator of light pulses encoding the identification number of that particular vehicle. U.S. Pat. Nos. 4,025,791 and 4,121,102 disclose similar systems.
The present invention provides an overall simplification in avoiding the need for two-way communication between the fixed location and a passing vehicle.
The objects and purposes of the present invention include provision of:
A vehicle monitor system capable of effective infrared transmission of data to a fixed ground station from a vehicle moving therepast despite wide variation in ambient light conditions from darkness to bright sunlight.
A system, as aforesaid, which automatically monitors and stores, within the vehicle, information relevant to vehicle condition, including miles traveled and fuel tank level, and which repetitively transmits such information and the identity of the vehicle via infrared light for reception at a ground station during movement of the vehicle therepast.
A system, as aforesaid, in which both the vehicle based transmitting unit and ground station based receiving unit include microprocessor circuitry.
A system, as aforesaid, in which the transmissions from the vehicle permit the ground station to operate devices responsive to vehicle approach, such as barriers, alarms or the like and to provide print-outs, relating to billing of rental vehicle use, vehicle maintenance or replacement, and the like, and in which the ground station is capable of supplying data to existing data processing equipment, such as billing equipment, of the system operator.
A system, as aforesaid, which is adaptable with little or no structural change to a wide variety of vehicle types, land based or otherwise, and to a wide variety of ground station purposes.
A system, as aforesaid, usable for monitoring vehicles of fleet operators, including monitoring of rental cars at, entering, or leaving car rental locations, and which is adaptable to a variety of fleet applications, as for utility vehicles such as telephone, gas and electric company truck fleets, taxi fleets and government fleets, and which is readily installable on and removable from vehicles without affecting the appearance or resale value of the vehicle.